PLENARY SESSION 1PLA

Monday, Feb. 21, 10:30 a.m. – 12:30 p.m., General Assembly Hall A (GRB)

Chairs: J.R. Schrieffer (NHFML/Florida), T.H. Geballe (Stanford U)

1PLA.1 RVB Redux: The "Big Tent" Theory of High T_c

P.W. Anderson, Dept. of Physics, Princeton University, Princeton, NJ 08544

Presenting Author: P.W. Anderson

A number of groups of theorists are approaching what appears to me to be the same theory of high-T_c superconductivity from different angles. This theory also seems to be more or less a continuation of the original "RVB" approach of our group in the late '80's. The central idea of this approach is that the pseudogap state in the underdoped region below T* is the "d-wave RVB" or "flux phase" of a spin-charge separated electron fluid, in which the spinons are paired with a d-wave gap. Opening a gap without charge condensation is costly in kinetic energy so at a lower temperature T_c, roughly proportional to the phase stiffness of the charge fluid, superconductivity must occur to allow pair hopping and restore the missing kinetic energy. At higher doping, the charge stiffness is so large that the two transitions must occur simultaneously as in BCS. But it is important that in both cases the "normal" fluid in which T_c or T* occurs is itself a charge-spin separated non-Fermi liquid, becaause only in such a fluid does the suprexchange interaction between spinons which motivates the formation of the RVB occur. Nothing in the above seems to be inconsistent with the work of Fisher et. al. or Lee et. al, and it incorporates ideas of Laughlin, Affleck and others. The neutron resonance appears to be a soft mode of the RVB associated with antiferromagnetism as originally suggested by Hsu and proposed in another form by Zhang.

1PLA.2 Quantum Criticality and Cuprate Phenomenology

Presenting Author: R.B. Laughlin

Abstract not available.

[1] N. Furukawa, T.M. Rice and M. Salmhofer, Phys.Rev.Lett. 81, 3195 (1998).

[2] C. Honerkamp, M. Salmhofer, N. Furukawa and T.M. Rice (in preparation).